- update to 0.30.4:
* Regression: a positional argument with an underscore used in
`@arg` decorator would cause Argh fail on the assembling stage.
* As reported in #204 and #206, the new default name mapping
policy in fact silently changed the CLI API of some scripts:
arguments which were previously translated as CLI options
became optional positionals.
Although the instructions were supplied in the release notes,
the upgrade may not necessarily be intentional, so a waste of
users' time is quite likely.
* To alleviate this, the default value for
`name_mapping_policy` in standard functions has been changed
to `None`; if it's not specified, Argh falls back to the new
default policy, but raises `ArgumentNameMappingError` with
detailed instructions if it sees a non-kwonly argument with a
default value.
* Please specify the policy explicitly in order to avoid this
error if you need to infer optional positionals (``nargs="?"``)
from function signature.
* Regression: certain special values in argument default value
would cause an exception (#204)
* Added a more informative error message when the reason is
likely to be related to the migration from Argh v0.29 to a
version with a new argument name mapping policy.
* A new policy for mapping function arguments to CLI arguments
is used by default
* If you cannot modify the function signature to use kwonly
args for options, please consider explicitly specifying the
legacy name mapping
* The name mapping policy `BY_NAME_IF_HAS_DEFAULT` slightly